1. Technical Field
The present invention relates to an optical recording medium having a plurality of guide lines and data regions which are defined between adjacent guide lines and usable for optically recording data therein.
2. Background Art
Hitherto, an optical recording medium of this kind has linear track guides and data regions.
Reading and writing of data are accomplished by a self-clock method in which synchronization is achieved by means of clock bits contained in the data, while tracking is conducted to follow up a track guide.
The conventional optical recording medium, however, suffers from the following problems due to the use of the self-lock method. Namely, once the lock of the tracking is broken due to, for example, a contaminant or flaw in the surface of the optical recording medium, reading of data fails until the next clock bit is read. In addition, erroneous reading of data tends to result after a relocking, due to the fact that there is no means for identifying the leading end of the data.